[Sync] Move //sync to //components/sync.

components/sync/protocol/synced_notification_specifics.proto

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Sync protocol datatype extension for synced notifications.
 // DO NOT USE: This datatype is deprecated.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 option retain_unknown_fields = true;
 
 package sync_pb;
 
 // This message is kept around for backwards compatibility sake.
-message SyncedNotificationSpecifics {
-}
+message SyncedNotificationSpecifics {}